Electrochemical Oxidative Phosphorylations of Glycine Derivatives with R2P(O)-H-Containing Compounds via C(sp3)-H Functionalisation

Herein, we report the development of transition-metal-catalyst- and external-oxidant-free electrochemical cross-coupling hydrogen-evolution chemistry involving glycine amides and diarylphosphine oxides. A broad range of biologically active alpha-aminophosphonates was obtained in moderate to good yields in a clean and sustainable manner. Moreover, the TBAB (tetrabutylammonium bromide) electrolyte was recycled four times without obvious loss of reaction activity. Moreover, this protocol was performed on the gram scale under slightly modified electrolytic conditions or in combination with continuous flow microreactor technology. Control experiments were used to disclose a possible free-radical mechanism.

Automated summary

In this report, a transition-metal-catalyst- and external-oxidant-free electrochemical cross-coupling hydrogen-evolution chemistry using glycine amides and diarylphosphine oxides was developed. Biologically active alpha-aminophosphonates were obtained in moderate to good yields in a clean and sustainable manner. The TBAB (tetrabutylammonium bromide) electrolyte could be recycled four times without noticeable reduction in reaction activity. Control experiments were conducted to reveal a possible free-radical mechanism.